On Wed, Mar 28, 2018 at 12:29 AM, Joseph Myers <jos...@codesourcery.com> wrote: > On Tue, 27 Mar 2018, Steve Ellcey wrote: > >> Here is another libmvec question. While testing on x86 I could easily make >> a loop with calls to sin, cos, log, exp, or pow and see them vectorized when >> I compile with -Ofast. But if I try making a loop with sincos, it does not >> get vectorized. Is that to be expected? > > The sincos libmvec functions have a rather peculiar ABI; see > <https://sourceware.org/bugzilla/show_bug.cgi?id=20024>; that may not be > well-suited to vectorization in most cases. So far new exports with a > different vector ABI (and corresponding different header declarations) > have not yet been added.
Note we "canonicalize" sincos calls to __builtin_cexpi () which has a nicer interface. The vectorizer could handle vectorizing that by looking for the sincos decl, see whether it is OMP simd annotated and then use that during code-generation. It might need some more massaging after all and there's a vectorizer bug for vectorizing sincos already. Oh, and "CSEing" sin() + cos () to sincos happens before vectorization already. Richard. > -- > Joseph S. Myers > jos...@codesourcery.com
